Humans Appear…Birds Disappear

Conservation biologists have been distraught for years over the human onslaught on biodiversity. Around the world, we have been bludgeoning, poaching, poisoning and overexploiting other species of plants and animals which share Earth with us at an ever-accelerating pace.

Worse yet, we have been degrading and destroying their habitats on a vast scale. Logging, road-building, inundating rivers and their floodplains behind dams, channelizing and diverting streams, paving over lands, dredging and filling wetlands, converting forests to croplands, displacing wildlife with livestock, overgrazing, scraping the ocean bottom with trawl nets – all of these relentless and increasing human actions damage, destroy, or disrupt wildlife habitats. The result is reduced or even endangered wildlife populations.

The comfortable, politically correct, default presumption of those environmentalists who dismiss population’s crucial role in environmental degradation is that only wealthy, self-indulgent (i.e., heavily consuming) people and industrial technology employed by ruthless, profit-obsessed corporations damage Mother Nature. Actually this is more than mere presumption; it is deep-seated prejudice.

According to this prejudice, traditional hunter-gatherer and shifting cultivation societies – “noble savages” – lived in a state of harmony and bliss with nature. They respected their fellow creatures and the “circle of life;” conservation and sustainability were integral to their cosmology and economies.

But this is a fantasy, popular with us “civilized” moderns, who feel an understandable sense of loss at the demise of so many traditional peoples and folkways as well as guilt that all surviving dominant societies, including our own, are implicated in their disappearance.

Now comes yet more scientific evidence linking one type of environmental impact – species extinctions – to the inexorable spread and growth of human populations who were neither selfish capitalists nor wielders of sophisticated and sinister technology.

Tim Blackburn is the Director of the Institute of Zoology in London, England. In a recent issue of the U.K. publication Population Matters he describes his recent research on how invasions by exotic organisms (including humans) are correlated with extinctions of native bird species on remote islands in the eastern Pacific Ocean.

Using new statistical techniques, Blackburn and his team modeled extinction rates while accounting for uncertainties in the fossil record, as well as variation in extinction rates among species and islands.

Their findings are both sobering and sad. The models suggest that around two-thirds of Pacific bird species went extinct shortly after the first humans arrived. More species vanished from drier and smaller islands; these underwent greater habitat destruction and have fewer natural sanctuaries from hunters. Flightless and large-bodied species like New Zealand’s moa were the preferred targets of these hunters, and were more likely to have been hunted to extinction.

Blackburn’s team’s results suggest that about 1,300 bird species on tropical Pacific islands disappeared following the arrival of the first humans. This is equivalent to about 10 percent of all bird species on Earth that existed at that time.

Hip environmental groups like Greenpeace and the Earth Island Institute – supported by the planet’s avant-garde rich people – love to scapegoat those same rich people (but not the hip ones!) for the destruction of the Earth. Blackburn’s research suggests that all humans can harm wildlife merely following the imperatives to survive, multiply, and prosper. Accordingly, around the world, burgeoning numbers of impoverished rural peoples chop down forests, pollute streams, and slaughter wildlife in the name of survival and prosperity, small as it may be.

Migration to cities or emigration to wealthier countries may release some of the demographic pressure, but it is quickly replaced by new births. Access to birth control and educational and employment opportunities for girls and women offer the only hope for sustainable development – and wildlife.